The wheelbarrow has been used for centuries to transport loads. In these many years, the functional design of the wheelbarrow has settled to what is believed to be the optimal design. However, the wheelbarrow has many inherently problems due to its functional design.
First, the wheelbarrow and the load must be substantially symmetrical about the mid-line that runs from the front wheel to the midpoint between the handles. If not handled properly by an operator, an improperly loaded wheelbarrow can become unbalanced, especially when turning, and fall to the side thereby undesirably dumping at least part of its load.
Second, lifting and dumping the load in a wheelbarrow can be physically demanding. To dump a load, the operator must have the strength to raise the handles and the coordination to avoid prematurely dumping it.
Third, lowering the handles shifts the center of gravity toward the operator and increases the load on the operator's hands.
Fourth, because the handles must be lowered to do so, wheelbarrows are very difficult to push up a hill or over an elevation such as a curb.
The above problems may be magnified for people with physical impairments or vertically challenged.
Dumping trailers also are used to transport loads. However, dumping trailers are designed to be used by hitching them to riding lawn mowers. That is, dumping trailers are not designed to be conveniently pushed by an operator. Furthermore, dumping trailers cannot fully dump a load due to their limited range of motion. Thus, the operator must physically remove the portion of the load that was not automatically dumped from the dumping trailer during the dumping action.